PREMISES AND EQUIPMENT - Summary of Premises and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	$ 65,408	$ 68,682
Less accumulated depreciation and amortization	27,884	30,481
Bank premises and equipment, net	37,524	38,201
Depreciation expense	2,700	2,600	$ 2,700
Land
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	8,786	7,825
Buildings and improvements
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	27,520	31,987
Leasehold improvements
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	6,216	3,926
Furniture and equipment
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	22,293	22,998
Construction in progress
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	$ 593	$ 1,946